Wi-Fi hotspots are simply not secure. They are the equivalent to you yelling everything you to everyone in the cafe. You might as well dictate the email you’re reading from you spouse to your neighbour.
So what can you do to prevent “en passant” eaves dropping? I’ll give you a few steps that can help you keep your information private.
Use VPN to Encrypt the Network Traffic
Use a VPN (Virtual Private Connection) to your office, home or third party VPN provider if possible when you are connecting to public Wi-Fi. VPN will encrypt the network traffic both ways as it travels over the air.
Use HTTPS to connect to web sites if VPN isn’t available

Firefox Secure connection example
If you don’t have access to a VPN, make sure that any sites you log into, such as hotmail, yahoo, twitter use a secure connection.
This type of connection will ensure that you have encrypted traffic from the server that is nearly for the average hacker impossible to snoop on.
Don’t use public computers
Public computers from an internet cafe are at the highest risk for having viruses, key loggers(password sniffers) and an array of tools onboard to grab your information. I would absolutely avoid these at all cost.
Purchase a mobile wireless modem
Rogers, Bell, Telus all have wireless modems that you can buy and pay a monthly fee to use. These devices typically plug into your USB port and connect to the internet using a cellular connection. These are encrypted devices and are much harder to eaves drop on.
In Conclusion
Just using these 4 steps is a good start. They are, of course, not the end all solution to all wireless security, but they are a step in the right direction. Sometimes the solutions will incur some costs, but a few dollars spent securing your information may save you a lot of money down the road if someone had access to your credit card information.